In the battle between the global warming warmists and the global warming skeptics, the center of the battle is well portrayed in these two graphs. The UN’s IPCC climate models have been based on Michael Mann’s discredited “hockey stick” graph which shows global temperature going along without much change until we reach the 20th century when temperatures climb sharply, much as the blade of a hockey stick does. (This is illustrated by the shadow of a hockey stick in the background).

Steven McIntyre and Ross McKitrick demolished the hockey stick graph in a number of papers that established that almost any numbers would produce the same configuration.

The elimination of the Medieval Warm Period from around AD 800-1300 made the hockey stick graph produce it’s ‘alarming’ 20th century rise, but conflicted with known history. It also eliminated the Little Ice Age of more recent history. Historian Arthur Herman has written about the “killing time”, the years beginning in 1695 when Scots suffered three failed harvests in a row.

“The crops were blighted by easterly “haars” or mists, by sunless, drenching summers, by storms, and by early bitter frosts and late snow in autumn. For seven years this calamitous weather continued… No one knows how many died during the famine of the Lean Years of 1697-1703, but they probably numbered in the tens of thousands.”

The lower graph represents the climatic changes in Europe over the past thousand years. The problem with temperatures is that the first mercury thermometer was invented in 1724 by Gabriel Fahrenheit. Beyond that we have to rely on proxy temperatures from such things as tree rings, ice cores and stalactites. The American thermometer record was supposed to be the most reliable, but locations of stations have cast doubt on that record, as many are located surrounded by pavement, or next to air-conditioner outlets and other urban “heat island” effects that makes the recorded temperatures too warm and unreliable.

Unfortunately for the hockey stick graph, people in Medieval times wrote about their fine weather and the things that they grew. The Vikings settled in Greenland and farmed. Now a new study has indicated that the rapid expansion of the Inca from the Cuzco area of highland Peru produced the largest empire in the new world between approximately AD 1400-1532, and led to the success of Machu Picchu.

A team of English and U.S. scientists has analyzed pollen, seeds and isotopes in core samples taken from the deep mud of a small lake near Machu Picchu. Their report says that “the success of the Inca was underpinned by a period of warming that lasted more than four centuries.” At its zenith the Inca culture was bigger than the Ming Dynasty China and the Ottoman Empire, the two major contemporaries.

It is worth mentioning that the entire hoopla about the dangerous warming of the past century is only about one degree of warming. Since 2002, the earth has been cooling again. The dangerous warming that requires us to rearrange our whole economy exists only in computer projections based on false history. GIGO.